Vehicle fueling system using double block and bleed fuel line

ABSTRACT

The invention is an improved method and system to fuel a vehicle such as a hydrogen-powered vehicle. The present invention vents air into a fuel fill line within the vehicle from a fuel fill receptacle to the vehicle&#39;s fuel storage tank. The invention eliminates or reduces inadvertent fuel ignition from electrostatic discharge in and around a vehicle fuel line during fueling. Just prior to fueling, the invention vents the fuel line in between two of a plurality of fuel line check valves closest to the receptacle. The invention can be configured to activate the vent system where a first switch indicates vehicle fueling is imminent (such as a fuel fill door is opened) and a second switch indicates that the receptacle is not attached to a fuel source. The system can also be configured to deactivate if the first switch indicates fueling is not imminent (the fuel door is closed), or the second switch indicates that the receptacle is attached to the fuel source. Additional features can include a calibratable timer to assure enough time has lapsed to assure proper fuel venting has occurred; a disable feature to disable the vent system when the vehicle is powered off; and indicators for the vehicle operator that the venting system is functioning.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to a vehicle fueling system and specifically to an improved method and system to fuel a vehicle using a fuel line with a double block and bleed.

[0003] 2. Discussion of the Prior Art

[0004] In an effort to find alternative energy sources for automobiles, hydrogen can be used in an electrochemical reaction to generate electricity. Generally, the reaction takes place in fuel cells. Fuel cells are known in the prior art for directly converting chemical energy of a fuel to electrical energy. Fuel cell advantages include low emissions, high fuel energy conversion efficiencies, and low noise and vibrations (U.S. Pat. No. 5,248,566 to Kumar et al.) Despite fuel cell advantages, various design challenges are presented by existing technology.

[0005] Fuel cell systems are typically fueled with hydrogen. Hydrogen fuel is highly volatile. When a hydrogen vehicle receives fuel, the vehicle physically connects to a hydrogen-dispensing nozzle. It is known that aircraft, marine vessels and ground vessels such as automobiles can accumulate significant electrostatic charges during transport. For a hydrogen-fueled vehicle, improper vehicle grounding or lack of grounding of the vehicle prior to connecting to the hydrogen fueling station could result in inadvertent igniting of any hydrogen present in or around the fueling line if an electrostatic discharge occurs.

[0006] Ways to reduce risks associated with the transfers of fuels are known in the prior art. For example, U.S. Pat. No. 4,091,848 to Phillips discloses a warning system for a liquefied petroleum (“LP”) gas transport vehicle. The system informs a vehicle's operator of a hose connection extending between a vehicle's gas tank and a second remote main supply.

[0007] U.S. Pat. No. 5,156,198 to Hall discloses a pump lock fuel system. The patent describes a fuel lock and dispensing system where data from a vehicle computer is used to identify the vehicle, to transfer data to and from the vehicle computer to a fuel pump computer and to unlock the fuel pump. The system will only allow fueling after a fuel nozzle is inserted and a vehicle identified. Although this patent provides an element of safety, its primary function is vehicle identification.

[0008] Automatic refueling systems are also known in the prior art. For example, U.S. Pat. No. 5,383,500 to Dwars et al. discloses an automatic refueling system that allows the driver to interrupt or modify refueling without leaving the vehicle. See also, U.S. Pat. No. 4,608,830 to Peschka et al. and U.S. Pat. No. 3,502,117 to Nebelsiek et al.

[0009] Vehicle grounding systems or other means to discharge electrostatic charges also exist in the prior art. See generally, U.S. Pat. No. 5,159,523 to Claassen et al. This system has a first and second grounding means and a detection circuit to verify proper grounding configuration before fueling is allowed. While Claassen et al. reduces accidental and untimely discharge of accumulated electrostatic discharges in the proximity of volatile fuels, it requires three complicated system components and does nothing to reduce the amount of volatile fuels present in and around a vehicle fuel line.

[0010] A simple and inexpensive system to eliminate or reduce inadvertent fuel ignition in and around a vehicle fuel line during fueling is needed.

SUMMARY OF THE INVENTION

[0011] Accordingly, the present invention provides an improved system and method to fuel a vehicle, particularly a hydrogen-fueled vehicle, by eliminating or reducing inadvertent fuel ignition in and around a vehicle fuel line during fueling.

[0012] The present invention has a receptacle to mechanically receive a fuel fill nozzle from a fueling station, a fuel line connected to the receptacle, and a storage tank connected to the fuel line; a plurality of check valves in the fuel lines; a system to vent the fuel line between the two check valves closest to the receptacle; and a system to activate and deactivate the vent system comprising a first switch to indicate vehicle fueling is imminent (such as a fuel fill door is opened) and a second switch to indicate that the receptacle is not attached to a fuel source. The switches can be electrical or mechanical.

[0013] The invention can be configured to be activated when the first switch indicates fueling is imminent and the second switch indicates that the fuel fill nozzle has been connected and a slight amount of fuel flow has started. In the preferred embodiment, when the fuel door opens, but before a fill station's fuel fill nozzle is attached, a mechanical or electrical 3-way solenoid valve activates and vents any hydrogen in the fuel line adjacent to the receptacle to a vent to the atmosphere. When the fuel fill nozzle is attached to the receptacle, a “puff” of hydrogen can be sent from the fueling station to flush any fuel line air from the vent cycle. The “puff” also activates the second switch to deactivate the 3-way solenoid valve. This ends the venting and allows hydrogen to flow into the vehicle tank. The venting system can be also be configured to deactivate if the first switch indicates fueling is not imminent (such as when the fuel door is closed).

[0014] The invention can add a calibratable timer to assure enough time has lapsed to assure proper fuel venting has occurred; a disable feature to disable the vent system when the vehicle is powered off; and indicators for the vehicle operator that the venting system is functioning.

[0015] The vented area of the fuel line in the preferred embodiment lies between the two check valves closest to the receptacle. This area should not be greater than six inches. Further, the closest check valve to the receptacle and the receptacle should be separated by a minimal distance or even adjacent to each other.

[0016] Other objects of the present invention will become more apparent to persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

[0017] The foregoing objects, advantages, and features, as well as other objects and advantages, will become apparent with reference to the description and figures below, in which like numerals represent like elements and in which:

[0018]FIG. 1 illustrates a prior art fuel line check valve system.

[0019]FIG. 2 illustrates the present invention including possible venting system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] The present invention relates to fuel transfer and specifically to an improved method and system to fuel a vehicle that eliminates or reduces inadvertent fuel ignition in and around a vehicle fuel line during fueling. Although the illustrated embodiment of the present invention is particularly suited to hydrogen fueling, the present invention itself can be adapted to many types of fueling strategies by someone of ordinary skill in the art.

[0021]FIG. 1 illustrates, by way of example only, a prior art hydrogen fueling system for a vehicle. A fueling station 20 connects to a vehicle 22 by way of a fill nozzle 24, the vehicle 22 having a receptacle 34 to mechanically receive the fill nozzle 24 from the fueling station 20. An on-board hydrogen storage tank 26 connects to the receptacle 34 by way of a fuel line 28 having a first check valve 30 and a second check valve 32. The plurality of check valves is often referred to as “blocks.”

[0022] The fueling system illustrated in FIG. 1 provides only a means to keep hydrogen from escaping back out the fuel line 28 when the fill nozzle 24 is released after fueling is complete. This has inherent shortcomings. In the next fueling cycle, if the vehicle 22 is not grounded or is improperly grounded to the fueling station 20 before the fill nozzle 24 touches the vehicle 22, an electrostatic discharge could ignite any fuel leaking back into the fuel line 28 from the first check valve 30.

[0023] The present invention illustrated in FIG. 2 provides a system to reduce or eliminate this risk. It uses not only double blocks, but also a system to ventilate or “bleed” any fuel leaking back into the fuel line 28 from the first check valve 30 before a fill nozzle 24 is introduced to the vehicle 22.

[0024] In FIG. 2, a fueling station 40 connects to a vehicle 42 by way of a fuel fill nozzle 44, the vehicle 42 having a receptacle 66 to mechanically receive the fuel fill nozzle 44. An on-board hydrogen storage tank 46 of the vehicle 42 connects to the receptacle 66 by way of a fuel line 48 having a first check valve 50, a second check valve 54, and a third check valve 52. The plurality of check valves is often referred to as “blocks.” The distance between the second check valve 54 and the third check valve 52, the valves closest to the receptacle 66, needs to be minimal to reduce contamination to the fuel line system by the small amount of air trapped in the fuel line 48 between those valves when they are vented as described below. In the preferred embodiment, this distance should be no greater than six inches. Further, the distance between the second check valve 54 and the receptacle 66 should be minimal, and the second check valve 54 and the receptacle 66 should be adjacent or attached to each other.

[0025] The present invention adds one of many possible venting systems to the fuel line 48. A venting system 3-way solenoid valve 58 (such as a prior art solenoid valve that is electrically actuated) is added to the fuel line 48 between the second check valve 54 and the third check valve 52, these valves being closest to the receptacle 66. The 3-way solenoid valve 58, when activated, opens that portion of the fuel line 48 to a vent 62 to outside air. The position of this “air-in” and “H2 out” vent 62 is important to allow passive venting. The 3-way solenoid valve 58 can be mechanical or electrical. The venting should be in an area away from a fuel fill door (not shown).

[0026] Fuel line 48 venting can be activated for a brief period of time with any event that the first switch such as a fill door switch 56, indicates vehicle fueling is imminent and a second switch, such as a pressure switch 60, indicates the receptacle 66 is not attached to a fuel source. In its normal position, venting is not activated since outside air in the fuel line 48 will promote corrosion and allow contaminates to enter. In the preferred embodiment, the venting system is activated by a first switch, such as the fuel door switch 56, indicating when fueling is imminent (such as when the fuel fill door (not shown) is opened). The fill door switch 56 can be mechanical or electrical. In FIG. 2, the system is shown in the “vented” position since the fill door switch 56 is in the “closed” position indicating the fuel fill door is open and hydrogen pressure has not yet activated a fuel pressure switch 60 (described below). This occurs after the operator has opened the fuel door but has not yet connected the fuel fill nozzle 44.

[0027] When the fuel line 48 is in the “vented” position, fuel cannot be added to the on-board hydrogen storage tank 46. Therefore, the system is only vented for a short period of time. When the fuel fill nozzle 44 is connected, a small “puff” of hydrogen is first sent to the fuel line 48. This will purge any air from the fuel line 48 and activate the pressure switch 60. This pressure switch 60, when activated, will indicate the receptacle 66 is attached, deactivate the 3-way solenoid valve 58, and close the vent 62 from the atmosphere. Fueling can then commence since the fueling station 40 is now connected to the on-board hydrogen storage tank 46. In the preferred embodiment, the pressure-activated switch 60 is a pressure activated electric slide switch. The switch can also be mechanical. FIG. 2 illustrates the pressure-activated switch 60 without pressure from the fuel fill nozzle 44. The venting system can also be configured to deactivate if the fuel door switch 56 indicates fueling is not imminent (such as when the fuel door (now shown) is closed).

[0028] In short, the present invention vents a small portion of the fuel line 48 susceptible to inadvertent static discharge prior to fueling when two conditions are met: the fuel fill door (not shown) is open and the fuel fill nozzle 44 is not connected. By venting the fuel line 48 near receptacle 66 before the fuel fill nozzle 44 contacts the vehicle 42, fuel will not be present and ignited by electrostatic discharge. As an additional feature, the present invention can also add indicators to assure the vehicle 42 operator that the venting system is functioning properly. Further, the invention can add a calibratable timer to assure enough time has lapsed to assure proper fuel venting has occurred. Also, the invention can be configured to disable the system to activate and deactivate the vent system when the vehicle 42 is powered off or shut down.

[0029] The above-described embodiment of the invention is provided purely for purposes of example. Many other variations, modifications, catalysts, and applications of the invention may be made. 

We claim:
 1. An improved vehicle fuel transfer system configured to interact with a fueling station, comprising: a vehicle comprising a receptacle to mechanically receive a fuel fill nozzle from the fueling station, a fuel line connected to the receptacle, and an on-board storage tank connected to the fuel line; the vehicle fuel line further comprising a plurality of check valves; a system to vent the fuel line between two check valves closest to the receptacle; and a system to activate and deactivate the vent system comprising a first switch to indicate vehicle fueling is imminent and a second switch to indicate that the receptacle is not attached to a fuel source.
 2. The system of claim 1 wherein vehicle fueling is imminent when a fuel fill door is opened.
 3. The system of claim 1 wherein the system to activate the vent system comprises a requirement that the first switch indicates fueling is imminent and the second switch indicates that the receptacle is not attached to the fuel source.
 4. The system of claim 1 wherein the distance between the two check valves closest to the receptacle is no greater than six inches.
 5. The system of claim 1 wherein the system to deactivate the vent system comprises a requirement that the first switch indicates fueling is not imminent.
 6. The system of claim 1 wherein the system to deactivate the vent system comprises a requirement that the second switch indicates that the receptacle is attached to the fuel source.
 7. The system of claim 1 wherein the system to activate the vent system further comprises a calibrated timer.
 8. The system of claim 1 wherein the first switch is mechanical.
 9. The system of claim 1 wherein the first switch is electrical.
 10. The system of claim 1 wherein the second switch is mechanical.
 11. The system of claim 1 wherein the second switch is electrical.
 12. The system of claim 1 further comprising a system to disable the system to activate and deactivate the vent system when the vehicle is powered off.
 13. The system of claim 1 further comprising indicators that let an operator know the vent system is functioning.
 14. The system of claim 1 wherein the venting system comprises a 3-way solenoid valve and a vent.
 15. The system of claim 14 wherein the 3-way solenoid valve is electrical.
 16. The system of claim 14 wherein the 3-way solenoid valve is mechanical.
 17. An improved vehicle fuel transfer method configured to interact with a fueling station, comprising the steps of: venting a fuel line comprising a plurality of check valves disposed between a vehicle fuel storage tank and a receptacle to mechanically receive a fuel fill nozzle from the fueling station, the venting occurring between two check valves closest to the receptacle; and activating and deactivating the venting comprising the steps of indicating vehicle fueling is imminent and indicating the receptacle is not attached to a fuel source.
 18. The method of claim 17 wherein the step of indicating vehicle fueling is imminent occurs when a fuel fill door is opened.
 19. The method of claim 17 wherein the step of activating venting comprises the steps of indicating fueling is imminent and indicating the receptacle is not attached to the fuel source.
 20. The method of claim 17 wherein the step of deactivating venting comprises the steps of indicating fueling is not imminent.
 21. The method of claim 17 wherein the step of deactivating venting comprises the step of indicating that the receptacle is attached to the fuel source.
 22. The method of claim 17 wherein the step of activating venting further comprises the step of timing the venting.
 23. The method of claim 17 further comprising the step of disabling venting when the vehicle is powered off.
 24. The method of claim 17 further comprising the step of indicating to the operator that the venting is functioning.
 25. The method of claim 17 wherein the distance between the two check valves closest to the receptacle is no greater than six inches.
 26. The method of claim 17 wherein the check valve closest to the receptacle is adjacent to the receptacle. 